Abstract: A wireless power transfer system includes a plurality of power sources and at least one power receiver, in which power transfer from the power sources to the power receiver is performed in wireless by using magnetic field resonance or electric field resonance. In the system, one of the plurality of power sources is designated as a master power source and the other one or more power sources are designated as slave power sources. In addition, the master power source controls the plurality of power sources and the at least one power receiver to perform the power transfer. This allows the system to perform the power transfer in an optimum state.

Abstract: A power receiver includes: a secondary-side resonant coil configured to receive electric power from a primary-side resonant coil through magnetic field resonance generated; a capacitor inserted in series in a resonant coil part of the secondary-side resonant coil; a series circuit, coupled in parallel with the capacitor, of a first switch and a second switch; a first rectifier coupled in parallel with the first switch, the first rectifier having a first rectification direction; a second rectifier coupled in parallel with the second switch and having a second rectification direction; a detector configured to detect the electric power received by the secondary-side resonant coil; and a controller configured to adjust phases of a first signal for switching on/off the first switch and of a second signal for switching on/off the second switch to adjust an amount of the electric power received by the secondary-side resonant coil.

Abstract: A power receiver includes: a secondary-side resonant coil including a resonant coil part to receive electric power from a primary-side resonant coil through magnetic field resonance; a capacitor inserted in series in the resonant coil part; a series circuit of a first switch and a second switch; a first rectifier having a first rectification direction; a second rectifier having a second rectification direction; a detector to detect a voltage waveform or a current waveform of the power; and a controller to adjust, in a state of adjusting a phase difference between the waveform and a driving signal that includes a first signal for switching on/off the first switch and a second signal for switching on/off the second switch to be a predetermined phase difference, a length of a period, during which the switches are both on, to adjust an amount of the power received by the secondary-side resonant coil.

Abstract: A power source includes a power source coil, a power transfer control unit, and a power receiver detection unit. The power source coil is configured to wirelessly transfer power to a power receiver using one of magnetic field resonance and electric field resonance, and the power transfer control unit is configured to control the power source coil. Further, the power receiver detection unit is configured to detect the power receiver by bringing the power receiver into proximity thereto or contact therewith.

Abstract: A power receiver includes: a secondary-side resonant coil including a resonant coil part to receive electric power from a primary-side resonant coil through magnetic field resonance; a first capacitor inserted in series in the resonant coil part; a series circuit of a first switch and a second switch; a first rectifier having a first rectification direction; a second rectifier having a second rectification direction opposite to the first rectification direction; a second capacitor inserted in series with the series circuit; a detector configured to detect a voltage waveform or a current waveform of the electric power; and a controller configured to adjust a phase difference between the waveform and a driving signal that includes a first signal for switching on/off the first switch and a second signal for switching on/off the second switch to adjust an amount of the electric power received by the secondary-side resonant coil.

Abstract: A power reception apparatus includes a plurality of power extraction coils that extract power from a coil being a power supply source, a switch that selects one of the plurality of the power extraction coils and connects the selected power extraction coil to a battery, and a controller that senses a charging state of the battery and changes over the switch. The plurality of the power extraction coils are different from each other in terms of a diameter, the number of turns, or a distance from the coil being the power supply source.

Abstract: A magnetic resonance electric power-transmitting apparatus in the magnetic resonance wireless electric power transmission system includes a resonance coil, an electric power-supplying unit which supplies electric power to the resonance coil to cause the resonance coil to generate a magnetic field, a magnetic material which varies a magnetic field generated by the resonance coil, and a position adjustment unit which adjusts a positional relationship between the resonance coil and the magnetic material.

Abstract: A power transmission device includes: a power supply circuit that generates an alternating voltage; a power transmission coil that receives an alternating voltage generated by the power supply circuit to thereby generate a magnetic field; a power transmission resonator that includes: a resonant coil; and a resonant capacitor and through which electromagnetic induction causes an electric current to flow when a magnetic field is generated by the power transmission coil to enter a resonance state; and a control circuit that controls the position or the orientation of the power transmission coil with respect to the power transmission resonator in the direction in which a standing wave ratio in a transmission line from the power supply circuit to the power transmission coil decreases.

Abstract: A power receiver includes a secondary-side resonance coil including a resonance coil part to receive power from a primary-side resonance coil by magnetic resonance; a capacitor in the resonance coil part of the secondary-side resonance coil; a series circuit of first and second switches connected in parallel with the capacitor; a first rectifier connected in parallel with the first switch, and having a first rectification direction; a second rectifier connected in parallel with the second switch, and having a second rectification direction opposite to the first rectification direction; a detector to detect a waveform of a power supply supplied to the secondary-side resonance coil; and a controller to adjust the waveform, and a phase difference between first and second signals to switch on and off the first and second switches, respectively, to adjust the power to be received by the secondary-side resonance coil.

Abstract: A power receiver includes: a first secondary-side resonant coil that receives electric power from a primary-side resonant coil through magnetic field resonance; a capacitor; a smoothing circuit; a pair of output terminals; a switch coupled in parallel to the capacitor or in series between a rectifier circuit and either a first terminal or a second terminal; and a drive controller that drives the switch through a first PWM drive pattern determined by a first duty cycle and by a first frequency that is less than or equal to a frequency of the magnetic field resonance. The first duty cycle is set based on a first efficiency of power reception of the first secondary-side resonant coil, a first rated output of a first load, a second efficiency of power reception of a second secondary-side resonant coil of another power receiver, and a second rated output of a second load.

Abstract: A wireless power supply system has a power sending resonance coil, a power receiving resonance coil, and a relay resonance coil. The power sending resonance coil has a predetermined resonance frequency characteristic, and transmits power wirelessly. The power receiving resonance coil has the same resonance frequency characteristic as the power sending resonance coil, and receives power wirelessly with a magnetic field resonance mode generated by synchronization of the resonance frequency. The relay resonance coil has the same resonance frequency characteristic as the power sending resonance coil and the power receiving resonance coil, and relay power from the power sending resonance coil to the power receiving resonance coil wirelessly with the magnetic field resonance mode generated by synchronization of the resonance frequency with them.

Abstract: A power transmitting apparatus includes a power transmission or reception circuit, a first coil connected to the power transmission or reception circuit through wires, a plurality of resonance coils having respective, different diameters one of which is selectively coupled to the first coil through electromagnetic induction, and a position control apparatus configured to control the positions of the resonance coils, wherein the position control apparatus is configured to selectively align an axial direction of one of the resonance coils with an axial direction of the first coil.

Abstract: In a resonant frequency control method in a magnetic field resonant coupling type power transmission system transmitting an electric power from a power transmitting coil to a power receiving coil using magnetic field resonance, a high-speed, accurate and real-time adjustment of the resonant frequency of a coil is realized. The phase of a voltage supplied to a power transmitting coil and the phase of a current that flows in the power transmitting coil or a power receiving coil is detected and the resonant frequency of the power transmitting coil or the power receiving coil is varied such that the phase difference between them becomes a target value.

Abstract: A power receiver which wirelessly receives power from at least one power source using one of magnetic field resonance and electric field resonance, including a power receiver coil, an internal circuit, a power detection resistor, a switch, a power reception control unit, and a communication circuit unit. The power receiver coil wirelessly receives the power from the power source, and the internal circuit uses the power obtained by the power receiver coil. The power detection resistor detects the power obtained by the power receiver coil, and the switch applies a received power voltage obtained by the power receiver coil by switching to the power detection resistor. The power reception control unit controls the power detection resistor and the switch, and the communication circuit unit performs communication with the power source, comprising detection information of a received power and power supply timing information.

Abstract: A power transmission apparatus includes a cover part attached to one of a power transmitter and an electronic apparatus, the power transmitter including a primary-side coil connected to an alternating-current power supply and a primary-side resonant coil configured to receive power from the primary-side coil by electromagnetic induction, the electronic apparatus including a secondary-side coil; and a secondary-side resonant coil disposed in the cover part, and configured to transmit to the secondary-side coil the power received from the primary-side resonant coil by magnetic field resonance generated between the primary-side resonant coil and the secondary-side resonant coil.

Abstract: A power transmitting apparatus includes a plurality of primary-side resonant coils disposed along a conveyance path of a plurality of electronic devices and configured to utilize magnetic field resonance to transmit electric power to secondary-side resonant coils of the respective electronic devices conveyed along the conveyance path; and a plurality of phase adjusters connected between an alternating-current source and the respective primary-side resonant coils and configured to respectively adjust phases of the electric power, supplied to the primary-side resonant coils from the alternating-current source, so as to uniform the phases of the electric power, supplied to the primary-side resonant coils from the alternating-current source.

Abstract: A power transmission device that adjusts the resonance frequency of a plurality of power transmitters with high precision, is provided. The power transmission device includes a first power transmitter and a second power transmitter that respectively adjust the capacitance such that a resonance frequency is attained, based on a variation degree of a phase difference with respect to a variation of the capacitance when the capacitance of a variable capacitance unit is varied, and the first control unit adjusts the resonance frequency of the first power transmitter in a state where the second power transmitter is off, and the second control unit adjusts the resonance frequency of the second power transmitter in a state where the first power transmitter is off.

Abstract: A power receiver includes a power receiver coil, a secondary battery, a load resistor, a switch, and a power receiver controller. The power receiver coil is configured to wirelessly receive power from a power source, and the secondary battery is configured to be charged by power from the power receiver coil. The switch is configured to selectively connect the power receiver coil to the secondary battery or the load resistor, and the power receiver controller is configured to control the switch in accordance with a power supply state of the power source based on the power receiver coil, and a charged state of the secondary battery.

Abstract: A power transmission device that adjusts the resonance frequency of a plurality of power transmitters with high precision, is provided. The power transmission device includes a first power transmitter and a second power transmitter that respectively adjust the capacitance such that a resonance frequency is attained, based on a variation degree of a phase difference with respect to a variation of the capacitance when the capacitance of a variable capacitance unit is varied, and the first control unit adjusts the resonance frequency of the first power transmitter in a state where the second power transmitter is off, and the second control unit adjusts the resonance frequency of the second power transmitter in a state where the first power transmitter is off.

Abstract: A wireless power supply system has a power sending resonance coil, a power receiving resonance coil, and a relay resonance coil. The power sending resonance coil has a predetermined resonance frequency characteristic, and transmits power wirelessly. The power receiving resonance coil has the same resonance frequency characteristic as the power sending resonance coil, and receives power wirelessly with a magnetic field resonance mode generated by synchronization of the resonance frequency. The relay resonance coil has the same resonance frequency characteristic as the power sending resonance coil and the power receiving resonance coil, and relay power from the power sending resonance coil to the power receiving resonance coil wirelessly with the magnetic field resonance mode generated by synchronization of the resonance frequency with them.